Trailer sidewall construction

ABSTRACT

A trailer for transporting bulk material has a container mounted on a chassis and wheeled suspension. The container has opposing sidewalls, a floor, a front wall, and a rear opening. The trailer further has an unloading system comprising a plow and a plow motor system. The plow is disposed in the container and shaped and sized to span substantially a transverse cross-section of the container. The plow motor system is operable to move the plow longitudinally in the container to urge or push the bulk material in the container toward and out of the rear opening of the container. At least one of the sidewalls comprises a removable panel installed longitudinally along a bottom of the sidewall, wherein an inward-facing surface of the removable panel and an inward-facing surface of the sidewall are substantially co-planar.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/472,902 filed Mar. 29, 2017, which is a continuation of U.S. patentapplication Ser. No. 15/237,891 filed Aug. 16, 2016, which is acontinuation of U.S. patent application Ser. No. 14/891,885 filed Nov.17, 2015, which is a National Phase Entry of CA2014/050887 filed Sep.17, 2014, which claims the benefit of priority of U.S. ProvisionalPatent Application No. 61/879,502 filed Sep. 18, 2013 which are herebyincorporated by reference.

FIELD

The present invention relates generally to the field of transportation.More particularly, the present invention relates to a trailer for thetransportation of bulk materials.

BACKGROUND

Trailers are commonly used for the transportation of bulk aggregatematerial such as gravel, stone, grain, coal, and the like. Generally, atrailer includes a chassis mounted on a wheeled suspension with wheelsfor rollably driving the chassis on the ground, and a rigid containercarried by the chassis. The rigid container comprises a floor, opposingsidewalls, a front wall, and a rear gate which may be opened forloading/unloading bulk materials into the container. The container mayinclude a roof, or may include a top opening for loading of bulkmaterials into the container. Some trailers include moving or walkingfloors for unloading the bulk materials transported by the trailer. Inorder to empty the container, some trailers include a plow whichcooperates with the moving floor to urge or push bulk material containedin the container toward and out of a rear-facing opening of thecontainer, and in this manner the container may be unloaded and emptiedof the bulk material without tilting of the trailer or container.

If materials are left over following an unloading operation of thewalking floor and plow, an operator such as a driver may have to enterthe container to sweep out the material that was left behind, especiallyif the driver is hauling a different material on the next load as inmost cases cross contamination of materials when switching betweenaggregate materials from load to load is undesirable. The expenditure ofsuch time and effort is undesirable, and moreover, for safety reasons,it is usually undesirable to have drivers entering the trailer to cleanthem out.

It is desirable, therefore, to make improvements to conventionalautomatic unloading and cleaning systems of walking floor trailers so asto maximum the amount of a carried bulk material which is unloaded byoperation of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described, by way ofexample only, with reference to the attached drawings, as follows.

FIG. 1 is a front perspective view of a trailer according to someembodiments.

FIG. 2 is a rear perspective view of the trailer of FIG. 1.

FIG. 3 is a rear perspective view of an embodiment of a container forthe trailer of FIG. 1.

FIG. 4 is a partial rear perspective view of a lower rear corner of thecontainer of FIG. 3.

FIG. 5 is a partial rear cross-sectional view corresponding to thepartial rear perspective view of FIG. 4.

FIG. 6 is a rear perspective view of another embodiment of a containerfor the trailer of FIG. 1.

FIG. 7 is a partial rear perspective view of a lower rear corner of thecontainer of FIG. 6.

FIG. 8 is a partial rear cross-sectional view corresponding to thepartial rear perspective view of FIG. 7.

FIG. 9 is a cross-sectional end view of a sidewall of the container ofFIG. 6.

FIG. 10 is a perspective view of a plow of embodiments of the trailer ofFIG. 1, wherein the plow is shown in isolation.

FIG. 11 is a side view of the plow of FIG. 10.

DESCRIPTION

The improved transportation trailer disclosed herein obviates ormitigates at least one disadvantage of conventional approaches describedabove.

The trailer is characterized by a longitude which extends parallel tothe sidewalls, and perpendicular to the front wall, and a transversewhich extends generally parallel to the front wall and generallyperpendicular to the sidewalls and longitude. The adjectives“longitudinal” and “transverse” are used herein consistently with thisdefinition of the longitude and transverse. The terms “bottom”,“downward”, “lower”, and the like are intended to indicate a positionrelatively proximal to a ground supporting the wheels of the trailer, ora direction proceeding generally from the top opening of the trailer tothe ground. Similarly, the terms “top”, “upward”, “upper”, and the likeare intended to indicate a position relatively distal from the ground,or a direction proceeding generally from the ground to the top openingof the trailer. The terms “inward”, “inwardly”, “inner”, and the likeare intended to indicate a position or direction relatively proximal toor toward a transverse center of the trailer, while terms such as“outward”, “outwardly”, “outer”, and the like are intended to indicate aposition or direction relatively distal or away from the transversecenter of the trailer.

FIGS. 1 and 2 show an embodiment of an improved transportation trailer100. The trailer 100 has a chassis (not shown) mounted on and carried bya wheeled suspension 102 including wheels for rollably driving thechassis on the ground, and a rigid container 104 mounted on and carriedby the chassis. FIG. 3 shows the rigid container 104 in isolation fromthe wheeled suspension 102, FIG. 4 shows a perspective view of a lowerrear corner of the container 104, and FIG. 5 shows an endcross-sectional view of the same lower rear corner. The rigid container104 comprises a floor 106 (shown particularly in FIG. 5), opposingsidewalls 108, a front wall 110, and a rear opening 112 (shownparticularly in FIG. 3) for loading/unloading bulk materials into thecontainer 104. The trailer 100 may also have a rear gate 114 which whenclosed retains the bulk materials in the container 104 and when openallows the bulk materials to be unloaded through the rear opening 112.The container 104 may include a roof or may include a top opening 116for loading bulk materials into the trailer 100.

In some embodiments, one or more of the sidewalls 108, front wall 110,and rear gate 114 are constructed of extruded aluminum panels, though itwill be appreciated that alternative materials and fabrication methodsare possible.

In some embodiments, the trailer 100 includes a moving or walking floor118 for unloading the materials transported by the trailer 100. Thewalking floor 118 includes a plurality of longitudinal slats 120provided in parallel and movable longitudinally back and forth in areciprocating manner. While in motion to load and/or unload materials inthe trailer 100, alternate slats 120 may move in opposite directions.

In some embodiments, the slats 120 are constructed of steel, though itwill be appreciated that alternative materials and fabrication methodsare possible.

The trailer 100 further has an unloading system including a plow 122having an upright blade 124 shaped and sized with so as substantially tospan a transverse cross-section of the container 104 perpendicular tothe longitude of the container 104. At the beginning of an unloadingoperation, the plow 122 is positioned near a forward end of thecontainer 104 proximal the front wall 110 and distal from a rear opening112 of the container 104, and is movable by the slats 120 of the walkingfloor 118 or otherwise toward the rear opening 112 of the container 104so as to urge or push the material contained in the container 104 towardand out of such rear opening 112, and in this manner the container 104may be unloaded and emptied of the material without tilting of thetrailer 100 or container 104.

The plow 122 is sized and shaped so as to provide only a slight gapbetween each lateral edge of the plow 122 and each inward-facing surfaceof an adjacent sidewall 108 of the container 104, so as to be fittinglyslidable therealong, in order to maximum an amount of the bulk materialcontained in the container 104 that is urged or pushed by the plow 122and emptied from the container 104.

In addition to the upright blade 124, the plow 122 may also have a plowbase 126 generally comprising one or more layered sheets of materialmounted near a bottom edge of the upright blade 124, and sized andshaped to span the container 104 transversely between the sidewalls 108and to extend a distance toward the rear opening 112. A top one of thelayered sheets may be made of a smooth and slippery material. The sheetsmay have any suitable thicknesses which may depend on the number oflayers and type of material used. The plow base 126 rests on the walkingfloor 118 and a bulk material loaded into the container 104 rests inpart on the plow base 126. The sheets of the plow base 126 may beflexible and take the shape of the floor to facilitate operation of theplow 122. Sufficient bulk material may be loaded onto the sheets tocreate sufficient downward pressure to facilitate movement of the plow122 steadily and consistently with the walking floor 118. The sheets ofthe plow base 126 may have the same length, or multiple lengths,suitable for facilitating movement of the plow 122 and the bulk materialresting on the plow base 126. In alternative embodiments, the plow base126 is flexible, as described above, or is rigid. During an operation ofthe plow 122, the plow base 126 carries part of the bulk materialresting on the plow base 126 as the plow 122 moves toward the rearopening 112 of the container 104. In some embodiments, when the plow 122reaches a rearmost extent of motion, the plow base 126 extendsrearwardly beyond rear opening 112 to assist in complete removal of bulkmaterial from the container 104.

In some embodiments, the plow 122, including the upright blade 124 andplow base 126, are constructed of steel, though it will be appreciatedthat alternative materials and fabrication methods are possible.

In some embodiments, the plow 122 is provided with a number of wipers128 formed of a sturdy but flexible material. Each wiper 128 is a stripof material mounted at a corresponding edge of the upright blade 124 ofthe plow 122, and which functions similarly to a squeegee, passing withcontact along an inward-facing surface of an adjacent sidewall 108 ofthe container 104 as the plow 122 moves longitudinally, to prevent ordeter passage of bulk material between the plow 122 and theinward-facing surface of the sidewall 108. A wiper 128 may be mounted ateach edge of the upright blade 124 of the plow 122 which is adjacent toand moves along a corresponding inward-facing surface of the container104, wherein the wiper 128 abuts and makes contact with theinward-facing surface. In some trailers 100 having this arrangement, andin connection with some kinds of bulk material, the provision of suchwipers 128 is sufficient to maximize emptying of the container 104.

In some embodiments, the flexible material is a Kevlar™ felt material;this material provides an advantage of heat tolerance, and can handlethe high temperature applications associated with hauling asphalt, forexample. Other embodiments use a rubber material, plastic material, orvinyl materials.

In some embodiments, as shown particularly in FIGS. 3 to 5, one of theslats 120 of the walking floor 118 is a corner slat 130 extendinglongitudinally along a bottom corner of the container 104 formed by thefloor 106 and an adjacent sidewall 108. The corner slat 130 extendsupwardly and transversely from the corner. A corner slat 130 may beprovided at each sidewall 108 of the container 104. The corner slats 130are useful for improving trailer 100 emptying during unloading ofvarious bulk aggregate materials. In configurations lacking corner slats130, a dead space is created at the adjacent corner which frustratesremoval of material therefrom.

While trailer containers are often constructed of a sturdy metal such assheet steel, sheet aluminum, or extruded aluminum panels, it issometimes desirable to construct at least a part of the inside of thecontainer of another material in order to achieve some desired result.For example, certain kinds of bulk material may exhibit lower frictionwith materials different from those typically used to construct trailercontainers, and thus it is desirable to provide inner surfaces of thecontainer with such lower-friction material if possible in order toreduce frictional resistance during unloading. This is especially, butnot exclusively, the case along sections of the inner sidewalls of thecontainer nearest the floor of the container where the greatest weightof material is applied to the inner surfaces of the container and thusthe greatest friction is experienced.

In addition, in cold climates, it is sometimes experienced that the bulkmaterial freezes thereby frustrating the unloading process, but that theprovision of materials other than typical container materials on insidesurfaces of the container may address this problem. For example, whileconstructing container sidewalls of extruded aluminum panels providescertain advantages, it is known that certain kinds of contents tend tofreeze more quickly in such containers than those constructed ofalternative materials such as steel. In such cases, it is desirable toprovide the sidewall with additional components which address theproblems associated with enhanced friction.

Thus, in some embodiments, to create a seal between a top edge of thecorner slat 130 and the adjacent sidewall 108, a removable panel 132 isinstalled along a lower portion of the sidewall 108, just above a cornerseal 134 (shown particularly in FIG. 5) which is mounted (by welding,with fasteners, or by any other suitable method) at an outside face ofthe corner seal 134 to the adjacent sidewall 108, and is supported frombelow by the floor 106 of the container 104. In some embodiments, theremovable panel 132 is installed by sliding the removable panel 132longitudinally into a channel sized and shaped for fittingly andslidingly receiving the removable panel 132 at an end of the channelproximal the rear opening 112. The removable panel 132 may be held inplace laterally by the corner slat 130 as well as a top cap 136 mountedto the sidewall 108 above the removable panel 132, wherein the top cap136 extends downwardly over the top of the removable panel 132 to coverthe top of the removable panel 132 and to prevent material from passingbehind the removable panel 132. The corner slat 130 may be formed withan upper tongue 138 along a length of the corner slat 130, wherein theupper tongue 138 is bent outwardly from a vertical plane of anupward-extending arm 140 of the corner slat 130. The removable panel 132may be formed with a slot 142 sized and shaped to receive the uppertongue 138 of the corner slat 130 such that when the upper tongue 138 isreceived in the slot 142 and an outward-facing surface of the cornerslat 130 contacts an inward-facing surface of the removable panel 132,the corner slat 130 holds the removable panel 132 traversely against theadjacent sidewall 108 while permitting longitudinal movement of thecorner slat 130 relative to the removable panel 132. In such case, theadjacent sidewall 108, the top cap 136, the corner seal 134, and thecorner slat 130 may be understood as forming the channel in which theremoveable panel 132 is received.

At the rear of the container 104, proximal to the rear opening 112, theremovable panel 132 may be bolted to a rear post 144, but the removablepanel 132 may be unrestrained at the front end of the container 104thereby allowing the removable panel 132 to expand and contract towardsthe front of the container 104 and avoid buckling, twisting, or otherdistortion due to thermal expansion and contraction. Alternatively, theremovable panel 132 may be mounted proximal to the front wall 110 of thecontainer 104, and in this respect may be bolted to a front post (notshown) or otherwise fastened near the front end while remainingunrestrained at the rear end of the container 104 to allow expansion andcontraction of the removable panel 132. A fastening plate 145 may beprovided for clamping the removable panel 132 to the rear post 144, andthe removable panel 132 may be provided with a recess or relief sizedand shaped fittingly to receive the fastening plate 145 such that whenthe fastening plate 145 is installed over the removable panel 132 toclamp the removable panel 132 to the rear post 144, the removable panel132 and the fastening plate 145 provide a flush inside-facing surface.The fastening plate 145 and the removable panel 132 may be provided withthrough holes sized and shaped to receive bolts 147 for passage throughto fastening at the rear post 144. The through holes in the fasteningplate 145 may be countersunk such that heads of the bolts 147 are alsoflush with inside-facing surfaces of the fastening plate 145 and theremovable panel 132.

In some embodiments, the removeable panel 132 has a length which isapproximately, and extends substantially an entire length of, thesidewall 108 in which it is installed, such that the removable panel 132extends substantially an entire distance between an inside-facingsurface of the front wall 110 of the container 104 and the rear post 144to which it is mounted, with allowance for longitudinal expansion. Inother embodiments, the removable panel 132 extends less than thedistance from the rear post 144 to the front wall 110, and in someembodiments the removable panel 132 extends toward a front of thecontainer 104 to about a forwardmost position of travel of the plow 122.

The removable panel 132 may be formed of ultra-high-molecular-weightpolyethylene (“uhmw”) or another desired material. Uhmw plastic iswidely used in the transportation industry in dump trailers to allowmaterial to slide out of the trailer with ease. It also acts as a verygood wearing material that can be easily replaced over time as itbecomes worn out. It is much easier to replace a uhmw removable panelthan to replace structural aluminum sheet or plate as it becomes wornout over time. On walking floor trailers, it is sometimes the lowestrear most portion on the sidewall that experiences the heaviest wear.

The corner seal 134 may be configured to provide support to the cornerslat 130, and in this regard the corner slat 130 may have, or be mountedto, at a lower side thereof a groove 146 sized and configured to receivea horizontal tongue 148 of the corner seal 134, such that the groove 148tends to resist vertical motion of the corner slat 130 along a length ofthe tongue 148. The corner seal 134 may also be configured to contactand support the corner slat 130 from beneath.

Providing the removable panel 132 on the sidewall 108 in this waycreates, however, an offset profile or ridge 150 inside the container104, as particularly shown in FIG. 5. The offset profile 150 mayinterfere with providing a seal between the plow wiper 128 andinward-facing surface of the container 104 during unloading therebypermitting material to slip past the wiper 128 and fall onto the walkingfloor 118 behind the plow 122. As noted above, providing a removablepanel 132 at a lower portion of the inward-facing surface of eachsidewall 108 of the container 104 is sometimes desirable, however, toprovide a lower-friction area during unloading.

In order to address the above issues, and to enable the use of removablepanels 132 such as plastic uhmw, while still enabling reliable unloadingof material using an automatic unloading system, an improved container200 having improved sidewalls 202 for use with improved removable panels204 is provided as shown in FIGS. 6 to 9. The container 200, sidewalls202, and removable panels 204 are respectively similar to the container104, sidewalls 108, and removable panels 132 described above, but withthe following improvements.

The improved sidewall 202 is provided with a sidewall relief 206 toreceive a removable panel 204, thereby providing the sidewall 202including the removable panel 204 with a flat, smooth surface inside thecontainer 200 with no offset profile. The removable panel 204 isfastened at the rear end of the trailer 100 to an improved rear post 207which is provided with a corresponding relief or recess. In oneembodiment, the sidewall 202 is manufactured from 1.5″ thick aluminumextruded panels, though it will be appreciated that other options may beused so long as the requisite structural integrity is provided. Eachsidewall 202 may be provided with a top panel having a top rail 209which is formed integrally with or welded to the top panel, therebysimplifying construction of the sidewall 202. Moreover, by providing anintegral extruded top rail 209, a savings in sidewall 202 weight isachieved along with improved structural characteristics as theadditional welding process ordinarily employed to connect a singular toprail profile to a sidewall assembly has been eliminated, thus in turneliminating the heat input ordinarily applied by the welding process.

It is desirable to select the thickness of the removable panel 204 so asto avoid excess warping and expansion and contraction when in directsunlight. In some embodiments a 0.75″ thickness of uhmw is used for theremovable panel 204 as it tends to keep its shape consistantly. Thisallows use of a 2.25″ aluminium extruded panel above and below theremovable panel 204, thus creating the smooth or flush inside surface.

As indicated above, the removable panel 204 is fastened to an improvedrear post 207 at the rear of the container 200, proximal to the rearopening 112, and may remain unrestrained at the front end of thecontainer 200 thereby allowing the removable panel 204 to expand andcontract towards the front of the container 200 and avoid buckling,twisting, or other distortion due to thermal expansion and contraction.As was the case with the container 104 above, an upper fastening plate205 may be provided for clamping the removable panel 204 to the rearpost 207, and the removable panel 204 may simlarly be provided with arecess or relief sized and shaped fittingly to receive the upperfastening plate 205 such that when the upper fastening plate 205 isinstalled over the removable panel 204 to clamp the removable panel 204to the rear post 207, the removable panel 204 and the upper fasteningplate 205 provide a flush inside-facing surface. Likewise, the upperfastening plate 205 and the removable panel 204 may be provided withthrough holes sized and shaped to receive bolts 147 for passage throughto fasten at the rear post 207. The through holes in the upper fasteningplate 205 may be countersunk such that heads of the bolts 147 are alsoflush with inside-facing surfaces of the upper fastening plate 205 andthe removable panel 204.

In some embodiments, the sidewall 202 may be constructed so as toprovide an integral corner seal 208 similar to corner seal 134. Forexample, where the sidewall 202 is constructed of extruded panels, suchas extruded aluminum panels, a bottom panel 210 of the sidewall 202 maybe extruded so as to include the integral corner seal 208, as shown inFIG. 8. In this way, welding or other fastening or joining of cornerseal 134 may be eliminated, while a structurally superior corner seal208 is provided. In particular, by avoiding the welding process normallyemployed to connect a side seal to a sidewall, the application of heatordinarily required for the welding process has been eliminated, and inthis way superior structural characteristics are achieved. In oneembodiment, the bottom panel 210 has a first thickness, for example2.25″, below the removable panel 204, and beginning at a top surface ofthe integral corner seal 208 has a second thickness less than the firstthickness, for example 1.5″ thick. The difference between the first andsecond thicknesses may be determined at least in part by, and may beprovided to make the sidewall relief 206 having a depth approximatelyequal to a thickness of the removable panel 204.

Providing the integral corner seal 208 enables lowering of the removablepanel 204 along the sidewall 202 to rest on the corner seal 208. By wayof comparison, in the embodiment of FIG. 5 the removable panel 132 isplaced above and rests atop an upper edge of the corner seal 134, thuscreating a gap at a rear end of the corner slat 130 between the cornerslat 130 and the rear post 144. In such a configuration, bulk materialsuch as stones tend to be caught in a gap (in some cases, a 0.84″ gap)and tend to scar the rear post 144 and dent the corner slat 130. Withthe removable panel 204 lowered and resting on an upper surface of theintegral corner seal 208, however, there is no gap at the rear forstones or other bulk material to be caught in, and the corner slat 130has only a small gap (in some cases, a gap of approximately 1/16″)between it and the rear post 144 at the rear of the trailer 100.

As noted above, sidewall 108 of container 104 has a top cap 136 mountedto the sidewall 108 to hold the removable panel 132 in place laterallyas well as to prevent material from passing behind the removable panel132. In the improved sidewall 202 of container 200, an integralretaining flange 212 is provided which assists in holding the removablepanel 204 in place laterally as well as sealing a top portion of theremovable panel 204 preventing material from passing in behind theremovable panel 204. The removable panel 204 may be machined orotherwise provided along the top portion with a retaining flange relief214 sized and configured to slidingly receive and cooperate with theretaining flange 212. The retaining flange relief 214 has aninward-facing surface which contacts and outward-facing surface of theretaining flange 212. An inward-facing surface of the retaining flange212 is substantially coplanar with the inward-facing surface of theremovable panel 204. In one embodiment, the sidewall 202 has a secondpanel 216 mounted above the bottom panel 210, and the second panel 216has a thickness of about 2.25″ thickness at the retaining flange 212,and a thickness of about 1.5″ at the along the sidewall relief 206.

In one embodiment, the removable panel 204 has a height of approximately15.75″ and is formed of uhmw, though it will be understood that otherdimensions and suitable materials may be used. The sidewall 202 panelsmay be configured so as to enable differently sized removable panels204. As noted, in other embodiments the removable panel 204 may beformed of different materials, and need not be limited to plastic uhmw.In some embodiments, the removable panel 204 could be formed of acomposite or steel or another aluminum extruded insert.

As noted above, the respective sidewalls 108, 202 and removable panels132, 204 of the above containers 104, 200 are provided to address theproblem of passage of bulk material past the wipers 128 of the plow 122.The inventors have made the surprising discovery that even very smallprofiles, ridges, or protrustions from the sidewall can result inpassage of bulk material past the wipers in some circumstances. Aprototype trailer similar to trailer 100 having container 200 wasmanufactured with sidewalls formed of extruded aluminum panels havinguhmw removeable panels, and additionally a 3/16″ thick aluminum linerwas welded to one of the sidewalls above the retaining flange. Thealuminum liner extended from just under a top rail of the sidewall toabout 0.75″ above the retaining flange on the second panel. It wasoriginally expected that this liner would not pose a problem forunloading. Upon testing removal of several loads of bulk materialincluding small stone chops, however, it was surprising observed thatthe bulk material could escape past this small transition area and fallon the floor behind the plow. Further tests were conducted wherein thebulk material was piled on one side of the container high above thistransition and the other side low just below the transition. The lowside cleaned out spotlessly with no material escaping past the plow,which on the high side material escaped past the transition area leavingmaterial behind. This problem was demonstrated on both sides of thetrailer. It was also observed during the unloading operation that smallstone chips clinged or grabbed onto the aluminum sidewall, whereas onthe uhmw removable panel the stone chip would simply slide along and notgrip the uhmw plastic, which also assisted in the positive unloadingresults. Without being bound to any particular theory, it is suspectedthat this behaviour results from certain combinations of sidewallmaterial, such as aluminum, and certain bulk materials, such as smallstone chips, wherein the materials have a greater tendency to cling,grab onto, or otherwise resist movement along the sidewall surface.

It has thus been determined that it is advantageous to have sidewallinside surfaces which are as flush as possible to achieve propermaterial unloading, with the inward-facing surfaces of all components,including the sidewall inner surface and the removable panel, beingcoplanar. It is believed that in some combinations this condition is metif no profile, ridge, or protrustion from the sidewall is greater than1/16″ in extension.

In order to achieve sidewall inner surfaces which are as coplanar aspossible, the removable panels 204 are sized and configured so as toprovide a precisely coplanar alignment of the inward-facing surfaces ofthe sidewall 108, removable panel 204, and the upward-extending arm 140of the corner slat 130. The removable panel 204 is machined or otherwiseprovided with a lower panel relief 218 along an upward-extending arm 140of the corner slat 130 of the walking floor 118 so as to provide arecess for receiving the upward-extending arm 140 of the corner slat130. In this way, an inward-facing surface of the upward-extending arm140 of the corner slat 130 may be made precisely coplanar with theinward-facing surface of the removable panel 204, which is coplanar withthe inward-facing surface of the aluminum sidewall 202 at the retainingflange 212. In this way, a fully coplanar inward-facing surface of theassembled container sidewall may be provided.

In some embodiments, a portion of the removable panel 204 near a rearend of the container 200 may be provided with a further inside-facingrecess or relief for receiving a lower fastening plate 213 for clampingthe removable panel 204 to the rear post 207 in cooperation with theupper fastening plate 205, and apart from its height is similar to theupper fastening plate 205. The lower fastening plate 213 may be disposedoutwardly of—that is, behind—the upward-extending arm 140 of the cornerslat 130. In some embodiments, the rear post 207 is formed of anextruded panel, which may be an extruded aluminum panel, and the reliefor recess in the rear post 207 for receiving the removable panel 204 isprovided by omitting during extrusion or machining away an inside-facingsurface of the rear post 207. In some embodiments, a further mountingplate 203 (shown in FIG. 7) is mounted to the rear post 207 in therelief or recess provided in the rear post 207, and the removable panel204 is mounted to the mounting plate 203 using the upper fastening plate205 and the lower fastening plate 213, such that the upper fasteningplate 205 and the lower fastening plate 213 each sandwich the removablepanel 204 and the mounting plate 203 with the rear post 207. In suchcase, the relief or recess provided in the rear post 207 has a depthsubstantially equal to a combined thickness of the mounting plate 203,the removable panel 204 at the rear post 207, and each of the upperfastening plate 205 and the lower fastening plate 213. In someembodiments, the removable panel 204 is provided with anotheroutside-facing recess or relief sized and shaped to receive the mountingplate 203. In any event, the components are so sized, shaped, andconstructed so as to provide a continuous, flush inside-facing surfaceof the removable panel 204 and the sidewall 202.

As noted above, in some embodiments the rear post 207 is formed of anextruded panel, which may be an extruded aluminum panel. The rear post207 may be provided with internal tabs, as part of the extrusionprocess, wherein the tabs are partial internal webs. The mounting plate203 may be plug welded or otherwise fastened to the internal tabs of therear post 207. The rear post 207 may be provided on an outside-facingsurface of the rear post 207 with through holes for providing access tonuts which cooperate with the bolts 147 to clamp the removable panel 204onto the mounting plate 203 using the upper fastening plate 205 and thelower fastening plate 213.

A further improvement for solving the problem of bulk material slippingpast the plow wipers is shown in FIGS. 10 and 11 which illustrate theplow 122 in isolation. In this embodiment, an additional secondary wiper220 is provided which assists in containing bulk material that may passthe wiper 128 which is a primary wiper. Once the plow 122 is moved tothe rear of the container 104 the driver or other operator can accessthe pocket 222 formed by the primary wiper 128 and the secondary wiper220 to scoop out or brush out any material that may have passed theprimary wiper 128. Alternatively, the plow 122 may be configured so asto travel sufficiently far toward the rear opening 112 of the trailer100 such that the secondary wiper 220 pushes the remaining materialentirely out of the container 104. The container 104 may further beprovided with a pathway or chute for such purposes. This variant isadvantageous for use with an aluminum sidewall wear plate which in someembodiments has a 3/16″ offset inside the container 104 where stonechips passing the offset location. Although a secondary wiper 220 isalso useful with containers 200 with a flush inside wall with no lineradded, a secondary wiper 220 may not be required.

The above embodiments are described in connection with a traileremploying a walking floor and an unloading system which may be a plowfor emptying the container of bulk material. It will be appreciated thatany sort of unloading system may be employed and the presently-disclosedsolutions advantageously applied. In particular, any type of plow motorsystem may be used, wherein plow motor system is understood to be themeans operable to impart motion to the plow to cause it to movelongitudinally in the container to urge or push bulk material along andultimately out of the rear opening. The plow motor system may includeany system, machinery, and source of motive force as is convenient andknown in the art. As described above, in some embodiments the plow motorsystem includes a walking floor which lifts and moves the plow. As shownin FIG. 2, the walking floor 118 may employ any suitable machinery 224to actuate and operate the walking floor 118. In other embodiments, thetrailer uses a hydraulic cylinder or the like for pushing the plow tothereby urge or push the bulk material out of the back of the container.In any event, the same problem of imperfect clearing of bulk materialmay be experienced with certain combinations of bulk material andsidewall material, with bulk material slipping past the plow wipers. Theabove solutions equally address this problem where a hydraulic cylinderis used instead of a walking floor.

Similarly, the same solution is applicable to any kind of container andany kind of unloading system where, because of the enhanced frictionresulting from the combination of bulk material and sidewall material,there is a tendency for the bulk material to slip past wipers wherethere is any ridge or protrusion from an inner surface of the sidewall.Such problem arises especially where removable panels such as uhmwplastic panels are used in order to obtain the benefits associated withtheir use. In any such case, the problem may be solved as describedabove, by providing a precisely coplanar arrangement of the respectiveinward-facing surfaces of all components of the sidewall.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments of the invention. However, it will be apparent to oneskilled in the art that these specific details are not required in orderto practice the invention. In other instances, well-known structures areshown in schematic or representative form in order not to obscure theinvention.

The above-described embodiments of the invention are intended to beexamples only. Alterations, modifications and variations can be effectedto the particular embodiments by those of skill in the art withoutdeparting from the scope of the invention, which is defined solely bythe claims appended hereto.

1. A removable panel for a sidewall of a container for transporting bulkmaterial, the removable panel comprising a body having a removable panelthickness and a tongue at a longitudinal upper edge of the removablepanel, the tongue having a tongue thickness less than the removablepanel thickness.
 2. The removable panel according to claim 1, whereinthe removable panel thickness is approximately equal to a depth of alongitudinal sidewall relief of the sidewall, wherein the sidewallrelief is sized and configured to slidingly receive the removable panel.3. The removable panel according to claim 2, wherein the tonguethickness is approximately equal to a width of a retaining slot formedby a gap between an outward-facing surface of a retaining flange of thesidewall extending downwardly into the sidewall relief and an opposinginward-facing surface of the sidewall relief, wherein the tongue issized and shaped to be received slidingly in the slot to retain theremovable panel in the sidewall relief.
 4. The removable panel accordingto claim 3, wherein the tongue is sized and shaped to be receivedlongitudinally in the slot.
 5. The removable panel according to claim 4,wherein an inward-facing surface of the removable panel is flush with aninward-facing surface of the sidewall when the removable panel isslidingly received in the sidewall relief.
 6. The removable panelaccording to claim 5, wherein the inward-facing surface of the sidewallcomprises an inward-facing surface of the retaining flange, and theinward-facing surface of the removable panel is flush with theinward-facing surface of the sidewall when the inward-facing surface ofthe removable panel is flush with the inward-facing surface of theretaining flange.
 7. The removable panel according to claim 5, whereinthe inward-facing surface of the removable panel and the inward-facingsurface of the sidewall are flush when the inward-facing surface of theremovable panel and the inward-facing surface of the sidewall aresubstantially free of any profile, ridge, or protrusion greater than1/16″ in extension from a plane of the surface of the removable paneland the surface of the sidewall.
 8. The removable panel according toclaim 1 comprising a lower panel relief sized and shaped, when theremovable panel is slidingly received in the sidewall relief, to receivean upward-extending arm of a corner slat of a walking floor mounted inthe container adjacent a bottom corner of the container formed at anintersection of the sidewall and a floor of the container.
 9. Theremovable panel according to claim 8 further comprising a corner slatslot sized and shaped, when the removable panel is slidingly received inthe sidewall relief, to slidingly receive an upper corner slat tonguebent outwardly from the upward-extending arm of the corner slat.
 10. Theremovable panel according to claim 1 formed ofultra-high-molecular-weight polyethylene.
 11. The removable panelaccording to claim 1 further comprising a fastening plate relief sizedand shaped to receive a fastening plate to clamp an end of the removablepanel, the fastening plate relief having a depth substantially equal toa thickness of the fastening plate wherein an inward-facing surface ofthe fastening plate is substantially flush with an inward-facing surfaceof the removable panel when the fastening plate is received in thefastening plate relief.
 12. The removable panel according to claim 11sized and shaped such that, when the removable panel is slidinglyreceived in the sidewall relief, the fastening plate is configured toclamp an end of the removable panel at a rear post of the containeradjacent an end of the sidewall relief.
 13. The removable panelaccording to claim 12 further comprising through holes in the fasteningplate relief, wherein the though holes are sized and shaped to receivebolts for passage through corresponding through holes in the fasteningplate to clamp the end of the removable panel.
 14. The removable panelaccording to claim 13 free of means to clamp a front end of theremovable panel at a front end of the container whereby the removablepanel is unrestrained at the front end of the container thereby allowingthe removable panel to expand or contract longitudinally.
 15. Theremovable panel according to claim 1, wherein the container constitutesa part of a trailer.
 16. The removable panel according to claim 1,wherein an upper portion of the tongue is outwardly beveled.
 17. Theremovable panel according to claim 1 comprising a corner seal reliefsized and shaped, when the removable panel is slidingly received in thesidewall relief, to receive an upward-extending arm of a corner sealextending inwardly from an inward-facing surface of the sidewall relief.18. The removable panel according to claim 1, comprising a chamferedoutwardly facing longitudinal lower edge.